Hatfield House is important to Sherlock Holmes (2009) because its historic Long Gallery was used as a filming location for a key scene. The estate is also known for hosting sets for many other popular films including the sequel to Sherlock Holmes: A Game of Shadows and movies like Batman and Tomb Raider. I found this information from Jason's Travels Blog online. This source is an example of singular authorship because Jason is the only author allowed to post on his blog. The blog does allow comments from other people and it seems there is a certain community that follows his blog. Mapping this location on COVE makes visible a place a "gatekeeper" may otherwise bury because some people might go straight to bigger names about travel information and facts about the location instead of looking for something more authentic.
Bibliography: https://jasonstravels.blog/2012/09/10/touring-englands-historic-hatfield-house/